The present invention relates to a connector for a fuel injection nozzle and a method of producing the same. More particularly, the present invention relates to a connector for a fuel injection nozzle usable for a motor-vehicle and a method of producing the same.
An internal combustion engine is known which includes a fuel delivery pipe to which a connector for a fuel injection nozzle is attached. An example of such an engine is illustrated in FIG. 15. In FIG. 15, reference numeral 2 denotes a cylinder block of an engine 1 in which a cylinder bore 3 is formed and a piston 4 is slidably disposed for reciprocation in the cylinder bore 3. A cylinder head 5 is arranged on the upper part of the cylinder bore 3, and an ignition plug 6 and suction valves 7 are disposed on the cylinder head 5. A suction manifold 8 is connected to the cylinder head 5 in a lateral direction, and a fuel injection nozzle 9 is slantwise attached to the upper part of the suction manifold 8.
As shown in FIG. 16 and FIG. 17, a delivery pipe 11 is connected to the fuel injection nozzle 9 via a connector 10 for the fuel injection nozzle 9. As shown in FIG. 15 to FIG. 18, the delivery pipe 11 has a rectangular cross-sectional shape, and one end thereof is closed and the other end has a conduit 12 connected thereto. Holes 13 are formed on the lower surface of the delivery pipe 11, and the connector 10 as shown in FIG. 19 and FIG. 20 is fitted into each of the holes 13 so that fuel can be fed into the fuel injection nozzle 9 via the delivery pipe 11 and the connector 10.
As shown in FIG. 19 and FIG. 20, the connector 10 includes a cylindrical fuel injection nozzle fitting portion 14 having an enlarged diameter and a delivery pipe connecting portion 15 having a reduced diameter and formed integrally with the fuel injection nozzle fitting portion 14. Each of the fuel injection nozzle fitting portion 14 and the delivery pipe connecting portion 14 is formed from a steel material by machining. An outwardly projecting position determining member 16 having a rectangular sectional shape is welded to the outer peripheral surface of the fitting portion 14, and the fuel injection nozzle 9 and the delivery pipe 11 are connected at predetermined positions by fitting the position determining member 16 into a recess in a main body of the fuel injection nozzle 9 and by fitting the connecting portion 15 into the hole 13 of the delivery pipe 11, whereby the fuel fed from the fuel injection nozzle 9 can be injected into the internal combustion engine 1 at a high efficiency.
In the conventional connector 10 as described above, the position determining member 16 is first fabricated from a steel material such as a round rod by the steps of machining, finishing and press-working and then welded to the injection nozzle fitting portion 14. For this reason, the material cost and working cost required for producing the connector 10 are unavoidably increased, and there is a further problem in that the thickness and weight of the convectional connector 10 cannot be reduced as desired due to a limitation to the machining operation. To eliminate these problems, it is thinkable to fabricate the connector from a steel sheet material subjected to deep drawing, but in this case other problems occur such as low dimensional accuracy, low productivity induced by deformation of the connector 10 due to thermal stress generated by subsequent welding or soldering of the position determining member to the connector.